The security industry has long used monitored alarm systems to report burglaries, fire, smoke, and similar alarm events. The typical monitored alarm system includes a control panel that receives data from sensors, intelligence that analyzes the data, and signaling components that report detected alarm events to a remote monitoring center. Alarm events are typically reported via a dial-up circuit switched data (CSD) connection to a public switched telephone network (PSTN) or other wireline network. The remote monitoring center resolves the event by notifying and/or dispatching appropriate responders, such as emergency medical services (EMS), local security personnel, firefighters, and police departments. Most alarm system control panels also include indicators that warn the occupants of the residence or facility of the emergency condition.
Standard phone lines may be unreliable, particularly because events such as intentional tampering, fires, and major calamities can compromise the physical communications infrastructure. To address the reliability issues, the alarm industry has developed methods of using wireless communications technology to supplement PSTN-based alarm systems, or as the sole means of communicating alarm events to remote monitoring centers.
Several approaches for wirelessly reporting alarm events have evolved in the industry. Perhaps the most basic wireless alarm event reporting system consists of a data interface to a dedicated cellular transceiver. Alarm signals and other messages can be routed over a voice channel via the dedicated cellular transceiver. As an example, the GSM 1000™ system transmits alarm signals over a GSM voice network.
Alternatively, digital signals may be transmitted over overhead control channels via a dedicated wireless device. For instance, the SKYROUTE™ transceiver uses the CELLEMETRY® wireless technology and the SS7/IS-41 network protocol to transmit short data messages without affecting the voice channels of the cellular network.
Another approach provides wireless alarm event reporting via a dedicated data-only packet-switched network, such as the narrowband MOBITEX™ mobile data technology developed by ERICSSON®. In contrast to the aforementioned systems, which use circuit-switched voice networks, a packet-switched approach obviates the need for dedicated connections for each reporting session, and potentially reduces the cost of each transmission, which is based on the number of packets sent rather than call connection time. However, this approach also introduces the additional cost of a dedicated radio modem that utilizes the Mobitex Interface Specification (MIS) open standard, which is administered by the Mobitex Operators Association.
In many of these approaches, the alarm system wirelessly communicates using the backup device only if the alarm system cannot access a landline telephone service. The backup device communicates with a mobile switching center (MSC), which authenticates the backup device and routes the call to a monitoring center.
In other approaches, the wireless communication technology is the primary or sole means of communicating with the remote monitoring center.
Typical wireless alarm event reporting approaches have several disadvantages. According to many such approaches, when an alarm event occurs, the alarm system control panel first attempts to transmit data over a PSTN connection. After detecting a transmission failure on the landline, the control panel determines that the landline is unavailable or disrupted, and transmits the data using the wireless backup device. Therefore, the alarm system only detects a loss of line integrity when the alarm system attempts to report another detected event. An alarm system that uses such a backup system may introduce a delay before reporting the disabled landline and any other alarm event. Some alarm systems attempt to address this shortcoming by periodically attempting a PSTN call to test the landline. However, this solution is imperfect due to the unnecessary disruption of the user's ability to access the landline during these tests. The test calls can also cause computer modems to lose carriers. Other alarm systems periodically check the telephone line for dial tone, but cannot detect loss of dial tone that occurs between scheduled checks.
The aforementioned systems determine the availability of a wireline connection before resorting to a backup system. To contrast, in the context of call forwarding, systems and methods have been developed for detecting the availability of a wireless device, and then performing a function in response thereto. However, these systems and methods are typically adapted to reroute to a wireline device incoming calls directed to the wireless device, rather than to route outgoing calls to the wireless device for completion.
Typical wireless event reporting devices can be expensive, due at least in part to the cost of the dedicated wireless device, service fees for access to cellular voice or data channels, and the cost of installation. Wireless alarm event reporting devices are commonly installed by making electrical connections between a telephone line and the monitoring device (such as an alarm system control panel), and between the monitoring device and a power source. Separate connections must also be made to connect the monitoring device to a radio or a cellular device, which relays the reporting data to a central station. The customer either directly or indirectly bears the cost of installation, which may require the expertise of an electrician or other professional. Furthermore, the alarm system control panel may have to be specially manufactured or modified to accommodate communication over a wireless network.
Thus, there is a need for a reliable, responsive, and less expensive system and method for providing a wireless backup to landline-based alarm systems for reporting alarm events to remote monitoring centers.